復制代碼 代碼如下:
class Fibonacci implements Iterator {
private $previous = 1;
private $current = 0;
private $key = 0;
public function current() {
return $this->current;
}
public function key() {
return $this->key;
}
public function next() {
// 關鍵在這裡
// 將當前值保存到 $newprevious
$newprevious = $this->current;
// 將上一個值與當前值的和賦給當前值
$this->current += $this->previous;
// 前一個當前值賦給上一個值
$this->previous = $newprevious;
$this->key++;
}
public function rewind() {
$this->previous = 1;
$this->current = 0;
$this->key = 0;
}
public function valid() {
return true;
}
}
$seq = new Fibonacci;
$i = 0;
foreach ($seq as $f) {
echo "$f ";
if ($i++ === 15) break;
}
程序運行結果:
復制代碼 代碼如下:
0 1 1 2 3 5 8 13 21 34 55 89 144 233 377 610